Air compressor



' Sept. 25, 1928.

J. A. DAVEY ET AL AIR COMPRESSOR 7 4 2 3 EFF: 5 1:; r 6 3 4 3 6 7 2 3 3 Z l| 1 :53. I: IE :i .il o o I l I i 1 I I I l Q i INVENTORS Sept. 25, 1928.

J. A. DAVEY El AL AIR COMPRESSOR Filed March 31, 1924 4 Sheets-Sheet 2 INVENTORS 7 'L Ma.

Sept. 25, T928. 7 1,685,150

J. A. DAVEY ET AL AIR COMPRESSOR Filed March 31. 1924 4 Sheets-Sheet 3 I I1 ll '1 II I INVNTORS 217 W (y r 7 Sept. 25, 1928. 1,685,150

J. A. DAVEY ET AL AIR COMPRESSOR Filed March 31, 1924 4 Sheets-Sheet 4 [I r C INVENTORS flL t. CI. W M W 7 TL; WW?- Patented Sept. 25, 1928.

UNITED STATES PATENT OFFICE.

JAMES A DAVEY, OF SOUND BEACH, CONNECTICUT, AND PAUL H. DAVEY AND CHARLES L. GAUGLER, OF KENT, OHIO; SAID GAUGLER ASSIGNOR OF ONE-THIRD OF HIS ENTIRE INTEREST TO THE DAVEY TREE EXPERT COMPANY, OF KENT,

OHIO, A CORPORATION OF OHIO.

AIR COMPRESSOR.

Application filed March 31, 1924. Serial N0. 703,098.

This invention relates to air compressors and particularly to a compressor of the portable type adapted to be coupled with an automotive vehicle for driving the compressor.

A portable air compressor of this type is of great value for supplying portable air driven tools, as, for example, saws, riveters or the like, and is particularly useful where the tools must be taken to the work in hand.

We provide an air compressor of simple and rugged construction which may be attached to the frame of an automotive vehicle and make operative connection to the engine thereof for driving the compressor. As the vehicle is always stationary when the compressor is in use, we provide auxiliary cooling means for the engine and also provide for cooling the compressor. This is preferably accomplished by placfng the compressor below the radiator of the vehicle and providing a fan in front of the radiator and above the compressor, the fan having blades adapted to deliver air in a generally axial direction for cooling the radiator and blades adapted to deliver air in a generally radial direction for cooling the compressor independently of the engine cooling means. If desired, a casing may be provided for directing the radially delivered air onto the cylinders of the compressor.

As above mentioned, it is exceedingly desirable to keep the compressor cool during operation and this is accomplished not only by providing cooling means, as above set forth, but also by discharging the compressed air from a cylinder directly against the walls of a reservoir which may be made of a metal having very high thermal conductivity, as, for example, aluminum. This construction, particularly when combined with the fan, maintains the compressor at a relatively low temperature and thus insures proper operation and long life of the valves. Moreover, the provision of a reservoir for each cylinder greatly simplifies the construction and supplies a suitable air reserve, making for smoother and more eflicient operation of the air driven tools.

In the accompanying drawings illustrating the present preferred embodiment of the invention- Figure 1 is a front elevation of a compressor constructed according to our invention and applied to the well-known Ford automobile;

Figure 2 is a vertical center line section through one of the cylinders and reservoirs of the compressor;

Figure 3 is a top plan view of the compressor, a fragment of the automobile being shown;

Figure 4 is a vertical center line section through the compressor, but with the reservoirs removed;

Figure 5 is a section, partly broken away, on the line V-V of Figure 4;

Figure 6 is a vertical section through the crank case of the compressor, showing one manner of making a power connection to the engine of the automotive vehicle;

Figure 7 is a section on the line VIIVII of Figure 6;

Figure 8 is a perspective View of the power connection shown in Figure 6;

Figure 9 is a vert'cal center line section showing another manner of making a power connection to the engine;

Figure 10 is a side elevation of a frame member of the automotive vehicle showing the attachment member for securing the compressor to the vehicle;

Figure 11 is a section on the line XI-XI of Figure 10; and

Figure 12 is a side elevation of the well known Fordson tractor showing the air compressor as applied thereto.

In the illustrated embodiment of the invention there is provided a crank case 2 having a pair of co-axial cylinders 3 attached thereto. The cylinders are provided with pistons 4 connected to a crank pin 5 by connecting rods 6. The crank pin 5 is carried between two flywheels 7 and 8, the flywheel 7 being secured to a shaft 9 adapted to make power connection with the engine of an automotive vehicle and the flywheel 8 being connected to a shaft 10 for driving the air compressor cooling fan.

Each cylinder is connected directly to a reservoir 11 of generally L-shaped longi tudinal section, this reservoir being preferably made of aluminum or other metal having a high heat conductivity and provided with cooling fins 12. As best shown in Figure 2, each reservoir is directly connected to its corresponding cylinder and the cooling fins 12 together with cooling fins 13 on the cylinder proper are effective for maintaining the entire apparatus at the desired low temperature. One arm of the L-shaped reservoir is shown as extending parallel to the cylinder, while the other forms a head for the same.

Each reservoir 11 is provided with an opening in line with the cylinder 3 and adapted to receive a basket-like frame member 14 for supporting the inlet and outlet valves of the cylinder. The frame member 14 comprises a central tube 15 having inwardly projecting lugs 16 for supporting a cross bar 17. A bolt 18 passes through the cross bar and is threaded into a valve seat member 19 having inlet ports 20 therein.

.A valve 21 is normally held against the seat 19 by springs 22 which are (arried by a spider 23. On the inlet stroke of the piston 4 air passes through the central tube 15 past the cross bar 17 and through the openings 20 into the cylinder. On the return stroke. the air" is compressed and leaves the cylinder through openings 24 in the valve seat 19, past a valve 25 normally held against the seat by springs 26, into the basket frame by way of ports 24' and into the reservoir 11 by way of openings 26' in the basket frame, which is also made of aluminum. When the compressed air is discharged through the basket frame into the reservoir it spreads outwardly and impinges on the walls thereof. This greatly facilitates cooling and aids materially in maintaining the compressor at the desired low temperature.

The basket frame 14 is held in place by cap screws27 and when these are removed the entire valve structure, as Well as the interior of the cylinder and the reservoir, is immediately accessible. The basket and the valve structure are removable as a whole from the (ompressor and the inlet valve may be replaced b removing a screw 28 which holds the spi er 23 in place, while the.

outlet valve 'may be replaced by loosening the bolt 18, turning the cross bar 17 until it is free of the lugs 16 and removing the valve seat member 19 from the basket frame 14.

The reservoirs 11 are connected by a conduit 29 and air is withdrawn from the compressor through a connection 30 which is preferably provided with a relief valve 31. The conduit 29 is preferably large, since this allows a very rapid communication of ressures between the reservoirs. As will lie apparent from the drawings, the two cylinders alternately discharge compressed air and the conduit 29 serves as an equallzer for the compressor. Ordinarily it will be found that the two reservoirs will be ample for any use to which the compressor may be put and air may be taken from the outlet 30 directly to the air driven tool. In some cases it may be desirable to interpose an additional reservoir in the system and this can be readily accomplished. In any event, the provision of a reservoir immediately adjacent the cylinder is of value, particularly in a portable compressor of this type, which is generally operated at high speeds with air cooling.

The compressor is attached to the frame of the automotive vehicle by an attachment plate 32 rigidly secured to the crank case 2. A pair of attachment members 33 are permanently secured-in the channels 34 comprising the frame of the vehicle and are provided with flanged and threaded ends 35 projecting beyond the radiator 36. The compressor is attached to the vehicle by engaging the attachment plate 32 with the threaded ends 35 and retaining it there with nuts 37.

The shaft 9 projects through the opening in the frame of the radiator 36 which is commonly provided for cranking the engine. On account of possible misalignment, due not only to small variations in dimensions of either the vehicle or the compressor but also due to the warping of the vehicle frame when the vehicle is standing on uneven ground, it is desirable to provide a flexible connection between the shaft 9 and the engine crank shaft 38. In Figure 6 there is shown one method of making such connection. The engine shaft 38 is provided with a close fitting sleeve 39 having a fan pulley 40 formed thereon for operating the engine cooling fan and provided with forwardly projecting lugs 41 for making a driving connection with the compressor shaft 9. The sleeve 39 is secured to the shaft 38 by bolts 42 passing through holes 43 in the sleeve 39. These bolts are set in substantially the position shown in Figures 6 and 7 while the sleeve is in process of making and the sleeve is then bored for the crank shaft. This leaves recesses 44 in one side of each bolt, as best shown in Figure 7. When the sleeve is put in place, the nuts 45 are tightened and p the recessed bolts are drawn up tightly against the shaft 39, resulting in an extremely powerful wedge action which solidly fastens the sleeve to the shaft 38. As seen in Figures 6 and 7, there are provided two pairs of bolts 42, the pairs being at right angles to one another. This construction is found in practice to be desirable in maintaining a tight connection between the shaft and the sleeve.

Loosely secured to the front end of the Ill] in the plate which are somewhat larger than the screws and thus allow a certain freedom of movement of the plate over the front end of the sleeve. This movement is limited to one direction as the lugs 41 fit closely in the slots 47 and the movement of the plate 42 can therefore only be radially of the lugs.

The shaft 9 carries a disk 50 having lugs engaging the pair of slots 48. This construction provides a connection which always makes a satisfactory drive from the engine to the compressor, even though the shafts are slightly out of alignment or if their axes became slightly inclined toward one another, as may occur under field conditions. No back lash occurs in this drive and the coupling is an extremely satisfactory one.

It is frequently desirable to leave the compressor in place while the vehicle is being moved from one object to another, and if desired, the disk 50 may be made slidable on the shaft 9, as shown in Figures 6 and 8, and provided with a pin 51 for holding it in or out of engagement with the disk 46, It will be understood that the compressor is only coupled or uncoupled when at rest and for this purpose the pin will be found satisfactory.

Figure 9 showns a modified structure wherein similar parts have been given the same reference characters with an a suflixed thereto. In this form a clutch is built into the crank case proper and a suitable connection adapted to be driven at all times is made with the engine shaft. This connection may take the form of a flexible coupling, as shownin Figures 6 and 8, or may be of other styles as desired.

The flywheel 7 is provided with a clutch jaw 52 and carries a ballbearing 53. The shaft 9 terminates adjacent the flywheel and is carried by the ballbearing 53 and a similar bearing 54 mounted in the crank case. A movable clutch jaw 55 is mounted on the shaft 9 and is provided with a clutch collar 56. A small arm 57 provided with a detent pin 58 is connected to the clutch collar 56 for moving the jaw 55 along the shaft on rotation of the arm 57, thus engaging or disengaging the clutch.

When the parts are in the position of Fig ure 9, the clutch is disengaged and the engine may be rotated without operating the compressor, the shaft 9* rotating in the bearings 53 and 54. When it is desired to connect the compressor, which is always done with the engine stationary, the arm 57 is turned to engage the clutch and thereafter rotation of the motor will turn the flywheel 7, at which time the parts are carried by the bearing 54 and a bearing 59.

Since the vehicle is always stationary when the compressor is operated, it is desirable to provide supplemental cooling for the engine as well as suitable cooling for the compressor. For this purpose we provide a fan 60 in front of the radiator 36 and immediately above the compressor, as best shown in Figures 1 and 3. This fan is provided with blades 61 adapted to deliver air in a generally axial direction and thus provides a strong blast through the radiator as long as the compressor is in operation. This materially aids in the operation of the apparatus, since it very effectively cools the engine, even though the car is standing still and with its engine working under maximum load.

The fan 60 is further provided with blades 62 adapted to deliver air in a generally radial direction for cooling the compressor. A casing 63 is provided as shown in Figures 1 and 3 for guiding the radially directed air against the cylinders and the reservoirs. We have found that with this construction the temperature of the compressor is maintained so low as to practically eliminate any of the usual valve and lubrication difficulties encountered in apparatus of this character.

The fan is mounted on an adjustable arm 64 secured to a bracket 65 carried by the crank case 2 and is driven by a belt 66 from a pulley 67 mounted on the shaft 10.

Figure 12 shows a compressor applied to the well known Fordson tractor. As is well known, this tractor is provided with an opening in the side of the frame for connecting a belt pulley or the like. We may attach the air compressor at this point by altering the attachment bracket 32, as will be apparent. It is desirable in such an in stallation, however, to provide a fan 60 for eachcylinder of the air compressor, as such a construction gives better'cooling in an installation of that character.

We provide an air compressor of simple construction which may be readily attached to an automotive vehicle. The reservoirs immediately adjacent the cylinders insure thorough cooling and provide suflicient storage space for all ordinary purposes and in a very small compass, while the connecting conduit is of value for quickly relieving the rise in pressure in the alternate cylinders on each stroke.

The provision of the cooling fan maintains the compressor at a relatively low temperature and greatly improves the operation thereof. The valves are very simple and efiicient and their construction and arrangement is particularly desirable in a com.- pressor of this type.

While we have illustrated one embodiment of our invention, it will be understood that it is not limited thereto, but may be otherwise embodied within the scope of the following claims.

We claim:

1. In combination with an automotive vehicle having an engine' and a radiator, an air compressor mounted adjacent the radiator, means for drivin the compressor from the engine of the ve iicle, a fan adapted to deliver cooling air to the compressor and to the radiator, and a casing surrounding the radiator and adapted to direct the air delivered by the fan.

2. In combination with an automotive vehicle having an engine and a radiator, an air compressor mounted below the radiator and forwardly thereof, means for driving the compressor from the engine of the vehicle, and a fan in front of the radiator and above the compressor, the fan being adapted to deliver air in a generally axial direction for cooling the radiator and also adapted to deliver air in a generally radial direction for cooling the compressor.

3. In combination with an automotive vehicle having an engine and a radiator, an air compressor mounted below the radiator and forwardly thereof, means for driving the compressor from the engine of the vehicle, a fan in front of the radiator and above the compressor, the fan being adapted to deliver air in a generally axial direction for cooling the radiator and also adapted to deliver air in a generally radial direction for cooling the compressor, and a casing for directing the radially delivered air.

4. In combination with an automative vehicle having an engineand a radiator, an air compressor having a reservoir and a cylinder discharging directly thereinto, the upper portion of the c 'linder being surrounded by the reservoir, the compressor being mounted below the radiator and forwardly thereof, means for driving the compressor from the engine of the vehicle, and a fan in front of the radiator and above the compressor, the fan being adapted to deliver air in a generally axial direction for cooling the radiator and being also adapted to deliver air in a generally radial direction for cooling the reservoir and the cylinder.

5. An air compressor having a cylinder, a piston, an L-shaped reservoir having one arm parallel to the cylinder and the other detachably connected to the cylinder, a. basket frame detachably secured in a cylindrical opening in the last-named arm, a

valve seat member at the inner end of the basket frame, a bolt in a central aperture in the basket frame detaehably securing the valve seat member thereto, a thin annular valve resiliently held against the valve seat member to close inlet ports therein, about said bolt, and a thin annular valve between the basket frame and the valve seat member, said last-named valve being resiliently held against outlet ports in the valve seat member leading to passages extending through the basket frame to said reservoir.

6. In an air compressor, a cylinder, a piston, a detachable head of metal of high heat conductivity, an annular basket frame encircled by said head and having passages opening toward said head, outlet ports leading from said cylinder to said passages, and means controlling the passage of air through said ports.

7. In an air compressor, a cylinder, a piston, a detachable head of metal of high heat (onductivity, an annular basket frame encircled by said head and having passages opening toward said head, outlet ports leading from said cylinder to said passages, said basket frame being seated in an outwardlyopening recess in the head whereby it may be removed independently of said head.

8. A device as in claim 6, said basket frame being seated in an outwardly-opening recess in the head whereby it may be removed independently of said head, and inlet and outlet valves carried by said basket frame.

9. In an automotive vehicle having an en- 'gine and a crankshaft, an air compressor having a shaft at the level of the engine crankshaft, cylinders spaced laterally of the compressor shaft, pistons in said cylinders, and L-shaped reservoirs each having one arm below and parallel to the cylinders and another arm providing a head for the corresponding cylinder.

10. A device as in claim 9, a cross-pipe connecting the reservoirs, and an outlet at the outer side of the cross-pipe.

In testimony whereof we have hereunto set our hands.

JAMES A. DAVEY. PAUL H. DAVEY. CHARLES L. GAUGLER. 

